var music_oneimg = document.getElementById("music_oneimg");
var music_twoimg = document.getElementById("music_twoimg");

music_oneimg.onclick = function() {
    var classs = music_twoimg.getAttribute('class');
    if (classs === "first_play") {
        // 添加指定的属性
        music_twoimg.setAttribute('class', 'first_no_play');
        //    setTimeout 定时器
        // 暂停
        setTimeout(function() {
            music_oneimg.style.animationPlayState = "paused";
            // document.getElementById("audio").pause();
        }, 10);
    } else {
        music_twoimg.setAttribute('class', 'first_play');
        music_oneimg.setAttribute('class', "play");
        // 运转
        setTimeout(function() {
            music_oneimg.style.animationPlayState = "running";
            // document.getElementById("audio").play();

        }, 10);
    }
}

var btn = document.getElementById("page_one");
btn.onclick = function() {
    document.getElementById("page_one").style.display = "none";
    document.getElementById("page_two").style.display = "block";

    setTimeout(function() {
        document.getElementById("page_two").style.display = "none";
        document.getElementById("page_three").style.display = "block";
    }, 5000);
}